Does London want 75 Canary Wharfs?

London is Europe's booming metropolis. A city state embracing half of South-East England, it is a magnet of money and style. It is rich, poor, dynamic, chaotic, selfwilled and hates being told what to do. I love it.

Is Ken Livingstone about to wreck it?

The Mayor is not bound by law to behave himself or stay sober or get on with those who disagree with him. But he is bound to produce a plan, a vision of the city's future, so others can do their business with confidence.

This week, Mr Livingstone's much-heralded London Plan goes out for public debate. I do not agree with it all, but it is the best plan the capital has seen for half a century. The wartime London County Plan saw London as a dispersed garden city. The Greater London Development Plan in 1976 accepted continuing decline. Amended by Mr Livingstone himself in 1984, it struggled absurdly to restore London's manufacturing base.

The new plan is modern and unashamedly boosterist. Its London is no glorified suburb. It defies pundits who predict that all cities are in terminal decline, wracked by crime and made obsolete by telecommunications.

The plan glories in the extra 700,000 people who have arrived in the past 15 years. It welcomes immigrants. A rising, ever-younger population shows a city is doing something right.

The plan boldly accepts higher living density. This means more crowds on the Tubes, more queues in hospitals, more traffic on the streets, higher property prices. But the plan is unequivocal. You cannot stop the tide, it says, so you should learn to manage success.

Here planning begins to bite. Sceptics might argue that London surged to success while nobody was in charge. For 15 years there has been no Mayor or London Assembly. Investment in roads, railways, schools and hospitals has been low. Infrastructure has been ignored. London is not bust. Why try mending it?

The answer is that London also grew fast in the Victorian era and was squalid and inefficient. Only at the end of the 19th century did public services catch up and only in the 20th was London able to rival Paris and New York in its quality of life. London must now plan for renewed expansion. Extra Tube capacity is 20 years overdue. Road traffic must be regulated. Suburban centres must see intensive commercial development. Mixed communities of private and public housing must keep London's neighbourhoods flexible and diverse.

So far so good. Where I part company with the plan is where I part company with Mr Livingstone. The plan's muscle lies in the concept of getting property developers to pay for social benefits. This selling of rule-busting planning permits has long been a fatal attraction to city politicians. It is what the old Labour London County Council did in the 1960s and 1970s. It pepperpotted central London with towers - always "beautiful" to their builders - as at Stag Place, Euston Tower, Notting Hill and Centre Point, to pay for road improvements. Margaret Thatcher's attempt at the same game, Canary Wharf, went bust. Its tax breaks and infrastructure grants made it the world's most heavily subsidised office block. Mr Livingstone wants "75 new Canary Wharfs".

Mr Livingstone's obsession with getting money from developers comes in part from central government leaving him no other source of revenue.

Property dealing and congestion charges are his only scope for cash. I sympathise. But that is no excuse for choosing advisers from within the developer community or " negotiating great deals for London" privately with property speculators. It leaves every corner of the capital at risk. When zoning and plot ratios can be overruled on a whim, nothing is certain. No neighbourhood and no skyline is safe. This is not planning but anarchy.

The Mayor's "edifice complex" is second only to his Sauvignon complex. The one is rectifiable, the other is not. High buildings are a foible, costly to maintain and cruel to their immediate surroundings. They have nothing to do with density. London was more densely inhabited in low-rise 1900 than it is today. The city is rich in sites for low-rise, high-density buildings and every developer knows it.

Where London is getting poorer is in the precious areas of history and character that Mr Livingstone regards as un-modern. These are the London that is attractive to inhabitants and newcomers alike: Covent Garden and Camden Town, Notting Hill and Borough Market, Shad Thames and Spitalfields. Such neighbourhoods were never ordered. Every one of them had to be saved in the teeth of opposition from the interests the Mayor now promotes.

London must study its history. The Mayor's arguments are the same as were used by his GLC forebears to try to flatten Covent Garden in the 1970s. They wanted the area to look like London Wall in the City. They willed the same fate on Camden Lock and King's Cross as they are now willing on Bishopsgate goods yard.

Those wishing to see what Mr Livingstone intends need only look from Westway at the cluster of architecturally dreadful slabs and towers rising over Paddington Basin. To the Mayor, this is a new Canary Wharf. To defend such monstrosities because they pay for social housing is absurd. It is like concreting Hyde Park to pay for housing in Haringey. These are not just eyesores, they are a wholly inappropriate use of planning as a way of raising tax revenue.

I repeat, this is not a bad plan. It has vision. But Mr Livingstone's failure to see the damage he can do to London's character, and thus its longterm appeal, is devastating. The new London is vulnerable to any deal he feels he can cut with his cronies. This offers business no certainty and local communities no security or confidence.

The Mayor says, Don't worry I'm an honest bloke, nobody gets away with murder. On present form, that is not enough.